JPH03277366A - Bag for medical treatment liquid - Google Patents

Abstract

PURPOSE:To maintain the resilience of the bag for medical treatment liquid and to improve the blocking resistance and transparency thereof by using the compd. of a proper ratio of specific branched low-density polyethylene(LDPE) for an inner layer and outer layer and using specific straight chain LDPE for an intermediate layer. CONSTITUTION:The compsn. consisting of 70 to 95wt.% straight chain LDPE which is a copolymer of ethylene and 1-olefin of >=0.920g/cm<3> density and 5 to 30wt.% branched LDPE of >=0.918g/cm<3> density obtd. by a high-pressure method is used for the inner layer and the outer layer and the straight chain LDPE of <=0.915g/cm<3> density is used for the intermediate layer. These layers are laminated. The bag having the resilience and mechanical strength and the excellent blocking resistance and transparency is obtd. in this way and, therefore, the practicable performance of the bag for medical treatment liquid is additionally improved.

Description

[Detailed description of the invention] [Background of the invention] , relates to a medical liquid bag for filling medical liquids such as nutritional liquids and therapeutic liquids.

<Prior Art> Conventionally, glass, polyethylene, polypropylene, soft polyvinyl chloride, ethylene/vinyl acetate copolymer, etc. have been used as containers for medical liquids filled with blood, medical solutions, etc.

There are generally two types of containers: bottle types made of glass or polypropylene, which emphasize independence, and bottles made of polyethylene, soft polyvinyl chloride, or ethylene-vinyl acetate copolymers, which are characterized by flexibility. A bag-shaped bag is used.

It is preferable that the bag-shaped container is more flexible from the viewpoint of handling, and more transparent so that the contents can be clearly seen, and such a container is desired.

However, in branched polyethylene and ethylene-vinyl acetate copolymer (hereinafter referred to as EVA) materials,
In order to ensure greater flexibility and transparency, it is preferable to use a low-density product for branched polyethylene, and a high-content vinyl acetate product for EVA. However, during the high-pressure steam sterilization process (generally heated to 110 to 120°C) with such materials, the inner surface of the bag-like container becomes blocked or fused, making it impossible to use it later as a medical bag. There are drawbacks such as the fact that

Also, JP-A-62-57555, JP-A-62-643
Linear polyethylene, which is flexible, has excellent transparency, and heat resistance, and is known from various publications such as No. The disadvantage is that flexibility and transparency are impaired in some areas. For example, linear polyethylene is a copolymer of ethylene and 1-olefin, and has better heat resistance and mechanical strength than branched low-density polyethylene obtained by a high-pressure method.

However, in medical liquid bags where flexibility is important, even if we try to ensure flexibility by simply optimizing the short chain branches produced and selectively reducing the density,
Since low-crystalline components are produced, blocking and fusion phenomena occur in the high-pressure steam sterilization process, which is undesirable.

Furthermore, if an attempt is made to increase the density in order to prevent such blocking and fusion phenomena, the flexibility and transparency will be impaired.

<Problems to be Solved by the Invention> Therefore, the present invention provides a bag for medical liquids that overcomes these drawbacks of the prior art and has excellent transparency, flexibility, heat resistance, blocking resistance, and mechanical strength. The purpose is to

[Summary of the invention]

Summary> As a result of intensive research in view of the above problems, the present inventor has discovered that
By using a blend of linear low-density polyethylene and a specific branched low-density polyethylene obtained by a high-pressure method in the inner and outer layers, and by using a specific linear low-density polyethylene in the middle layer, it can be used for medical liquids. The inventors have completed the present invention by discovering that the above objects can be achieved by maintaining the flexibility of the bag and dramatically improving blocking resistance and transparency.

That is, the medical liquid bag of the present invention has an inner layer and an outer layer made of linear low-density polyethylene 70, which is a copolymer of ethylene and 1-olefin with a density of 0.920 g/caf or more.
~95% by weight and density 0.918g obtained by high pressure method
/cj or more branched low density polyethylene 5-30% by weight
and an intermediate layer having a density of 0.915 sr/cm.
It is characterized by being a linear low density polyethylene having a density of 3 or less.

Effect> The bag for medical liquids of the present invention uses a mixture of appropriate amounts of linear low density polyethylene and a specific branched low density polyethylene obtained by a high pressure method in the inner and outer layers, and has a specific linear low density polyethylene in the middle layer. By using chain low-density polyethylene, it is possible to create bags that have flexibility and mechanical strength, as well as dramatically improved blocking resistance and transparency. This makes it possible to further improve the practical performance of liquid bags.

[Detailed description of the invention]

[1) Bag for medical liquids (1) Structure The bag for medical liquids of the present invention is for filling medical liquids such as Ringer's solution, nutrient solution, therapeutic liquids, etc., and basically has an inner layer and an inner layer on the front and back surfaces of the intermediate layer. It is a film-like or sheet-like laminate with outer layers laminated on top of each other with the inner layers facing inside, and then heat-sealed to form a bag shape. The bag typically has a hanging device or a mouth formed therein.

(a) Inner layer and outer layer The linear low-density polyethylene used for the inner layer and outer layer of the medical liquid bag of the present invention is ethylene and usually has a carbon number of 12.
It is a copolymer with 1-olefin or less, and the 1-olefin
Typical examples of olefins include butene-1, hexene-1,
1,4-methylpentene-1, octene-1, etc. are preferred. Depending on the copolymerization ratio, these 1-olefins lead to a decrease in the number of short chain branches and thus to a decrease in density, which affects various physical properties.

Among such linear low-density polyethylenes, the inner and outer layers of the bag have a density of 0.920 f/cm3 or more,
Preferably, a material having a weight of 0.923 g/7 or more is used. The upper limit of the density of this thing is 0.935g/c! II
If the density is higher than this, the flexibility will be poor, while if the density is less than the above, the heat resistance will be poor, which is not preferred.

The branched low-density polyethylene as the other component constituting the inner layer and outer layer has a density of 0 obtained by a high-pressure method.
．． 918g/ca1 or more, preferably 0.920-0.
The material is 930g/i. Since the density is low, the upper limit of the density is usually about 0.935 g/cIj, but it is not limited to this as long as the effects of the present invention can be achieved.

However, if the density is higher than this, flexibility is likely to be lost, while if the density is lower than this, the heat resistance will be poor.

Note that when low-density polyethylene obtained by a method other than the high-pressure method is used, for example, as shown in Comparative Example 4 below, the blocking property and transparency are not satisfactory.

The proportions of the linear low density polyethylene and branched low density polyethylene are 70 to 95% by weight of the former and 5 to 30% by weight of the latter, preferably 80 to 95% by weight of the former and 5 to 20% by weight of the latter. If the former is too small, heat resistance will be poor, while if it is too large, blocking properties and transparency will be poor, which is not preferable.

In addition, in the medical liquid bag of the present invention, the inner layer surface may be uneven (
Japanese Patent Publication No. 57-6947 and Japanese Patent Publication No. 60-24675
7) also uses a specific branched low-density polyethylene contained in the inner layer, making it easier to form fine and homogeneous irregularities.

(b) Intermediate layer The linear low-density polyethylene used in the intermediate layer of the medical liquid bag of the present invention is the same kind of linear low-density polyethylene used in the inner and outer layers described above, but has a density of 0. ．．
915g/C11 or less, preferably 0. 9 ] Og
/ctp or less.

The lower limit of the density of the material used for the intermediate layer is 0.890g/
If the density is lower than this, the mechanical strength and heat resistance will be poor, while if the density is higher than the above-mentioned density, the flexibility will be unsatisfactory.

(c) Other components The components of each layer constituting the medical liquid bag of the present invention are as described above, but in these components, other resin components, rubber, stabilizer,
Additional components such as colorants, lubricants, antiblocking agents, fillers, etc. may be included.

(2) Thickness Also, the thickness of each layer of this medical liquid bag is such that the inner layer is usually 1
0 to 100 μm, preferably 30 to 60 μm, intermediate layer usually 50 to 500 μm, preferably 150 to 300 μm
1 outer layer is usually 10 to 100 μm 1 preferably 30 to 60 μm
μm, and the preferable range of the thickness of the entire laminate formed by laminating these layers is 0.15 to 0.5+on. 0.1
If it is less than 5+++m, the sense of mass is likely to be impaired;
．． If you exceed 5 points, you will start to lack flexibility. The thickness ratio of each layer is not particularly limited, but in order to provide sufficient flexibility, the thickness of the intermediate layer should be 60% of the total thickness of the laminate.
% or more, particularly preferably 70 to 85%.

[■] Manufacture of bag for medical liquid The bag for medical liquid of the present invention can be manufactured by a film manufacturing method such as the general coextrusion inflation method or coextrusion T-die method used for polyethylene, EVA, polypropylene, etc. From the viewpoint of transparency, water-cooling and quenching co-extrusion methods can be used. In particular, the MFR of the low density polyethylene used in each of the above layers is JIS
- 6760 MFR of 0.1 to 10 g/10 minutes is preferred.

[Experiment example]

Evaluations in the Examples and Comparative Examples shown below were performed by the methods shown below.

Flexibility: Judgment was made by measuring the elastic modulus according to the test method of I5o-R-1184.

Transparency: Pour physiological saline into the obtained medical liquid bag,
Judgment was made by visual observation.

Blocking property: Judgment was made by observing the state of adhesion between the films on the inner surface of the water-cooled coextruded blown film.

Heat resistance: Visual judgment was made by observing the appearance after high-pressure steam sterilization treatment (110° C.).

Tensile strength: Judgment was made by measuring the strength at tensile breakage according to JIS-6760 test method.

Example 1 As a linear low density polyethylene for inner and outer layers,
80% by weight ethylene/hexene-1 copolymer with an MFR of 2.0 g/10 min (measured by JIS K6760 test method) and a density of 0.920 g/cm3 and an MFR of 1. Og
A mixture of 20% by weight of branched low-density polyethylene with /10 minutes and a density of 0.920 r/cat was used, and a copolymer of ethylene and hexene-1 was used as the linear low-density polyethylene for the intermediate layer. MFR is 2.0g/10min and density is 0.900g/cI! Using the ethylene/hexene-1 copolymer of Manufactured a bag.

This laminated film was evaluated and the results shown in Table 1 were obtained.

Example 2 As linear low density polyethylene for inner layer and outer layer, M
FR is 2.0g/10min and density is 0.920g/ci
80% by weight of ethylene #4-methylpentene-1 copolymer with FMR of 1.0 g/10 min and density of 0.9
20wt% branched low density polyethylene of 20r/cat
Also, as the linear low-density polyethylene for the intermediate layer, MFR is 2. Or/10 minutes and density is 0
．． 900g/cId of ethylene 4-methylpentene
Evaluation was carried out in the same manner as in Example 1 using 1 copolymer.

Example 3 As linear low density polyethylene for inner layer and outer layer, M
FR is 2.0g/10min and density is 0.920g/c#
80% by weight of ethylene-butene-1 copolymer of i and M
FR is 1.0g/10min and density is 0.920g/ci
A mixture of 20% by weight of branched low-density polyethylene was used, and as a linear low-density polyethylene for the intermediate layer,
MFR is 2.0g/l, 0 minutes and density is 0.900g/
Evaluation was carried out in the same manner as in Example 1 using an ethylene-butene-1 copolymer with cI11.

Example 4 M as linear low density polyethylene for inner and outer layers
FR is 2.0g/10min and density is 0.920g10j
95% by weight of ethylene-butene-1 copolymer and MF
R is 1. Og/10 minutes and density 0.920r/cat
Using a mixture of 5% by weight of branched low density polyethylene,
In addition, M
FR is 2.0g/10min and density is 0.900r/ca
Evaluation was performed in the same manner as in Example 1 using the ethylene-butene-1 copolymer of t.

Comparative Example 1 M as linear low density polyethylene for inner and outer layers
FR is 2.0g/10min and density is 0.920g/ci
98% by weight of ethylene/butene-] copolymer and MF
R is 1.0g/yuO and density is 0.920g/crt
Using a mixture of 2% by weight of branched low-density polyethylene of R, and as a linear low-density polyethylene for the intermediate layer,
MFR is 2, Og/10 min and density is 0.900g/c
Evaluation was carried out in the same manner as in Example 1 using the ethylene-butene-1 copolymer of m.

Comparative Example 2 As linear low density polyethylene for inner layer and outer layer,
MFR is 2.0g/10min and density is 0.920g/c
60% by weight of ethylene-butene-1 copolymer of d and M
FR is 1. Of/1. ．． 0 minutes and density is 0.920sr
A mixture of 40% by weight of branched low-density polyethylene of /Cll1 was used, and as a linear low-density polyethylene for the intermediate layer, the MFR was 2.0 g/10 min and the density was 0.9.
Evaluation was performed in the same manner as in Example 1 using an ethylene-butene-1 copolymer of 00 g/ca.

Comparative Example 3 As linear low density polyethylene for inner layer and outer layer,
MFR is 2.0g/10min and density is 0.920g10
80% by weight of ethylene-butene-1 copolymer of j and M
FR is 1.0g/10min and density is 0.920g/cI
A mixture of 20% by weight of branched low-density polyethylene of I was used, and as a linear low-density polyethylene for the intermediate layer, MFR was 2, Or/10 min, and density was 0.925+r.
Evaluation was carried out in the same manner as in Example 1 using an ethylene-butene-1 copolymer of /cd.

Comparative Example 4 M as linear low density polyethylene for inner layer and outer layer
FR is 2. Or/10 minutes and density is 0.920g/cm
Using the ethylene-butene-1 copolymer of No. 3, the MFR is 2.0 g/L as a linear low density polyethylene for the intermediate layer.
Evaluation was carried out in the same manner as in Example 1 using an ethylene-butene-1 copolymer having a density of 0.900 g/cj for 10 minutes.

Claims (1)

[Claims] The inner layer and the outer layer are 70 to 95% by weight linear low density polyethylene which is a copolymer of ethylene and 1-olefin with a density of 0.920 g/cm^3 or more and a density of 0.918 g/cm obtained by a high pressure method. A medical liquid bag comprising a composition comprising 5 to 30% by weight of branched low-density polyethylene with a density of ^3 or more, and an intermediate layer made of linear low-density polyethylene with a density of 0.915 g/cm^3 or less. .